Saturday, February 09, 2008
Antartica sits on active volcano
In February's edition of Nature Geoscience there is an interesting article about a volcano. While volcanoes are interesting in their own right, this one stood out because it is an active volcano that is erupting under Antarctica. The volcano, situated on the West Antarctic Ice Sheet, first erupted in 207 BC—about 2,000 years ago—and remains active to this day.
This volcano is not directly observable—its existence was discovered due to a layer of ash covering an elliptical area nearly 23,000 km2 that resulted from a past eruption. The data was gathered by the British Antarctic Survey, which puts the volcano's location in the Hudson Mountains at 74.6oS 97oW. Lead author of the study Hugh Corr of the BAS says that "[they] believe this was the biggest eruption in Antarctica during the last 10,000 years." The authors state that the substantial blast blew a hole in the ice sheet and shot a plume of ash and smoke over 12 km in the air.
As Antarctic glaciers are disappearing, this find offers up a new clue to the puzzle. The Pine Island glacier on the West Antarctic sheet has been accelerating its flow towards the coast, and its proximity to this newly found volcano could help explain the speed up, as residual heat from past eruptions could produce a source of water to lubricate the glacier's flow. However, the authors point out that the larger problem of glacial thinning in the West Antarctic sheet cannot be explained in full by this event, and they theorize that warming ocean waters play a large role.
This volcano is not directly observable—its existence was discovered due to a layer of ash covering an elliptical area nearly 23,000 km2 that resulted from a past eruption. The data was gathered by the British Antarctic Survey, which puts the volcano's location in the Hudson Mountains at 74.6oS 97oW. Lead author of the study Hugh Corr of the BAS says that "[they] believe this was the biggest eruption in Antarctica during the last 10,000 years." The authors state that the substantial blast blew a hole in the ice sheet and shot a plume of ash and smoke over 12 km in the air.
As Antarctic glaciers are disappearing, this find offers up a new clue to the puzzle. The Pine Island glacier on the West Antarctic sheet has been accelerating its flow towards the coast, and its proximity to this newly found volcano could help explain the speed up, as residual heat from past eruptions could produce a source of water to lubricate the glacier's flow. However, the authors point out that the larger problem of glacial thinning in the West Antarctic sheet cannot be explained in full by this event, and they theorize that warming ocean waters play a large role.
# posted by kevin : 10:55 AM
